/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.gallery3d.data;

import com.android.gallery3d.R;
import com.android.gallery3d.app.GalleryApp;
import com.android.gallery3d.util.Future;

/**
 * 组合源
 * 
 * @author lewa
 *
 */
// ComboAlbumSet combines multiple media sets into one. It lists all sub
// media sets from the input album sets.
// This only handles SubMediaSets, not MediaItems. (That's all we need now)
public class ComboAlbumSet extends MediaSet implements ContentListener {
	private static final String TAG = ComboAlbumSet.class.getSimpleName();
	private final MediaSet[] mSets;
	private final String mName;

	public ComboAlbumSet(Path path, GalleryApp application, MediaSet[] mediaSets) {
		super(path, nextVersionNumber());
		Log.d(TAG, "ComboAlbumSet");
		mSets = mediaSets;
		for (MediaSet set : mSets) {
			set.addContentListener(this);
		}
		mName = application.getResources().getString(
				R.string.set_label_all_albums);
	}

	@Override
	public MediaSet getSubMediaSet(int index) {
		Log.d(TAG, "getSubMediaSet -- index: " + index);
		for (MediaSet set : mSets) {
			int size = set.getSubMediaSetCount();
			if (index < size) {
				return set.getSubMediaSet(index);
			}
			index -= size;
		}
		return null;
	}

	@Override
	public int getSubMediaSetCount() {
		Log.d(TAG, "getSubMediaSetCount");
		int count = 0;
		for (MediaSet set : mSets) {
			count += set.getSubMediaSetCount();
		}
		return count;
	}

	@Override
	public String getName() {
		Log.d(TAG, "getName");
		return mName;
	}

	@Override
	public boolean isLoading() {
		Log.d(TAG, "isLoading");
		for (int i = 0, n = mSets.length; i < n; ++i) {
			if (mSets[i].isLoading())
				return true;
		}
		return false;
	}

	@Override
	public long reload() {
		Log.d(TAG, "reload");
		boolean changed = false;
		for (int i = 0, n = mSets.length; i < n; ++i) {
			long version = mSets[i].reload();
			if (version > mDataVersion)
				changed = true;
		}
		if (changed)
			mDataVersion = nextVersionNumber();
		return mDataVersion;
	}

	@Override
	public void onContentDirty() {
		notifyContentChanged();
	}

	@Override
	public Future<Integer> requestSync(SyncListener listener) {
		Log.d(TAG, "requestSync");
		return requestSyncOnMultipleSets(mSets, listener);
	}
}
